“Infradig”
is one of those words that sounds like it came out of the Hippie days
of 60s America. However, in fact, it is a shortened version of the
Latin phrase, “infra
dignitatem”
which means “beneath one’s dignity” and in this
form, it came from the distinguished critic, artist, and philosopher,
William Hazlitt.
The
first occurrence of the shortened form “infradig” shows
up in 1825 in a novel of Sir Walter Scott. The attitude incorporated
by the term is ironically at odds with those who it might be imagined
would use it. Imagine a wealthy matron chastising her daughter for
having an interest in rap music. It would be infradig of her to use
the term “infradig”. So, instead she might tell her
daughter: “Penelope, your interest in that so-called music is
infradignitatem!”
And one can imagine her rebellious daughter saying: “Are you
for real? Like what are you saying?”

In
any case, my point here is twofold: 1) I love the eccentricities of
language and 2) infrared images are perfectly respectable in the
microscopic community and I’ll try to demonstrate that to you.

For
reasons that I no longer recall, some of my images turned out to have
a distinct light-rose tint and others a light-blue tint. I’ll
show you one of each here. The first is of a large tree in a
neighbor’s yard and the second is the foot of a fly.

The
only alteration I made in these 2 images was to reduce size for the
Micscape format, otherwise they are untouched.

The
next image is of a juniper bush along the stairs leading up to our
front porch. It looks as though there is lots of snow but, in fact,
this is simply a result of the infrared–the image was taken in
spring after the snow had melted. This appearance is not uncommon
with shrubbery and trees.

It
is psychologically more comfortable to transform this image by using
the monochrome function which also, in my view, reveals a bit more by
sharpening the image.

This
next scene is part of our side-yard and this is a very dominantly
green scene.

However,
infrared and especially the monochrome transformation show us that
green becomes snow-colored with infrared.

Furthermore,
infrared/monochrome reveals to us that tulips are really albino
plants.

Visually
things start to get really interesting when we begin to look at
insect structures. Consider the remarkable detail of the hairs on
this fly.

It
is even more remarkable when the infrared image is transformed to
monochrome.

And
here is the foot of a fly–an interesting structure of an
obnoxious creature.

Dave Walker has done a fascinating article in which he uses a modified
system employing a video camera. He presents some images of insects
which using near infrared produces results that almost look like
X-rays.

Perhaps
the most interesting results which I have obtained thus far are of a
radula and some of sea cucumber spicules.

Let’s
start with the radula. A valuable lesson which I learned from
experimenting with this image is that one can produce some views that
provide enhanced contrast and interesting shifts in perspective.

Then,
by shifting the light level, cropping the image very slightly, and
altering the background, I was able to achieve an image in which the
teeth were emphasized, but in which the tissue was rendered more
transparent in such a way that a bit more detail is revealed.

Now,
by applying the INVERSE function to this image, we can see the teeth
as being pseudo-transparent while the tissue is rendered semi-opaque
creating an interesting contrast.

It
next occurred to me that it might be worthwhile to look at the teeth
quite apart from any surrounding tissue, so I created a white
background and painted out all of the tissue. Here is the result.

Then
I thought, why not apply the INVERSE function to this image and see
what it produces and here again there are some nice subtle visual
hints regarding structure within the teeth.

Finally,
I took a few images of calcareous spicules from a sea cucumber and
I’ll show you 2 of them.

Note
that in the largest spicule near the center, there are some
diffraction patterns which suggest a bit about the complex morphology
of these crystalline structures.

And
here is an image which shows some of the variety of types of spicules
in this same sea cucumber.

As
with most optical techniques, one has to select the “right”
sort of specimen types. Clearly, infrared will not give useful
results with all types and so it is important to choose those which
allow one to explore the dimensions that are unique to this approach.
I look forward to doing some further investigations with a different
range of specimens in the near future and if I find some intriguing
goodies, I’ll share them with you.